Johannesburg - Optimum Coal Holdings confirmed on Friday it had received expressions of interest from unnamed third parties, a day after sources close to the deal said commodities trader Glencore was eyeing the miner.
Optimum, South Africa's sixth-largest coal producer, said in a statement it had received "unsolicited, non-binding expressions of interest from third parties to acquire a controlling interest in Optimum".
At current prices, Optimum has a market capitalisation of around $1bn.
"Shareholders are advised that there is currently no certainty that Optimum will receive a firm intention to make an offer from any party," it added, giving no further details.
Optimum had already issued a cautionary statement earlier this month, alerting investors to circumstances which could affect its share price, but had denied having been approached by any prospective buyer.
The sources close to the deal had told Reuters on Thursday that Glencore and its partner
Cyril Ramaphosa were talking to Optimum shareholders and were preparing to make an announcement.
Shareholders in Optimum confirmed they had received an offer from the commodities giant and Ramaphosa, whose unlisted Shanduka Resources owns 30% of Shanduka Coal, a venture with Glencore.
Shanduka Coal, 70% owned by Glencore, has until recently been Glencore's vehicle for investment in coal mining in South Africa.
OCH, formerly owned by miner BHP Billiton, will produce 13.7 million tonnes of coal in 2011, up from 13.6 million in 2010.